Silver Dendrite Decorated Microporous Copper Structures for Enhancement of Nucleate Boiling Heat Transfer

This study explores the augmentation of nucleate boiling heat transfer by surface modification of copper surface through a combination of electrodeposition and galvanic exchange reaction. A novel microporous copper network adorned with silver dendrites was synthesized to boost the nucleate boiling heat transfer of deionized water. The boiling characteristics, such as heat transfer coefficient, wall superheat, and bubble dynamics, were experimentally studied for a microporous copper deposit with silver dendrites prepared at varying concentrations of silver ions (100, 200, and 400 mg/L) and immersion times (60, 80, and 300 s). Among the samples tested, the microporous copper deposit coated with silver dendrites at 400 mg/L for 300 s (sample S5) exhibited the most substantial enhancement. Compared to the performance of the bare copper surface, sample S5 demonstrated a remarkable 163.61% increase in the heat transfer coefficient and a significant 61.11% reduction in wall superheat. This enhancement can be attributed to the well-developed silver dendrites and the availability of micropores, facilitating hinderance-free bubble emanation. Also, other factors that are responsible for enhancement are high purity of the microporous and silver dendrites coating, and the surplus nucleation sites provided by the dendritic nature of silver.